Spark plug



Sept. 5, 1933.

SPARK PLUG A. GOODHEIM ET AL,

Filed April 28. 1931 mmf Y Tee whe] R wdM m 1M .A 6P. IT. m Mw Patented Sept. 5, 1933 UNITED STATES SPARK PLUG Albert Goodheim, North Bergen,

and William R.

Meyer, Union City, N. J.

Application April 28, 1931.

Serial No. 533,431

s claims. '(cl. 12a- 169) This invention relates to spark plugs and particularly to the provision of a hot plate or element disposed adjacent the spark terminals or" the plug for the purpose of. preheating the fuel charge 5 passed into the cylinder and disposed adjacent the spark plug terminals to facilitate the initial starting of the engine without performing the usual choking operations as is the common practice in the operation of starting internal combusl tion engines of various kinds and classes; and the object of the invention is to provide a hot plate or heating element coupled with the inner end portion of a spark plug and including an electric heating coil arranged adjacent the plate or ele- 15 ment, whereby the same will be heated in the completion of the circuit through said coil, whereby a predetermined amount of the fuel charge admitted into the cylinder and arranged adjacent said plate or element will be preheated or vapor- 20 ized to such degree as to facilitate igniting of the .fuel charge by the spark plug in the operation of starting the engine; a further object being to provide a heating element of the class described in the form of a plate including a conical portion 25 within which is arranged a heating coil, the latter being preferably contained in a body of insulating material; a further object being to provide means for insulating the circuit wire leading to the coil from the body of the plug; a still further object 39 being to provide a spark plug, the bore of which is disposed eccentrically to the axis of the plug, to provide a relatively large body portion at one side of the plug through Which the wire leading to the heating coil is passed and in connection 35 with which the terminal for such wire is mounted;

and with these and other objects in View, the invention consists in a device of the class and for the purpose specified, which is simple in construction, emcient in use and which is constructed 49 as hereinaiter described and claimed.

The invention is fully disclosed in the following speciication, of which the accompanying drawing forms a part, in which the separate parts of our improvement are designated by suitable ref- J" erence characters in each ol the views, and in which:

Fig. l is a side and sectional view of a spark plug made according to our invention; and,

Fig. 2 is a section on the line 2 2 of Fig. l.

ln the accompanying drawing, we have shown for the purpose of illustrating one use of our invention, a porcelain or other insulating core 5, in which the central terminal 6 of the spark plug is mounted. Said terminal extends through the 'n upper end of the core and is secured in position by a nut 7. A milled nut 8 is in threaded engagement with the core to secure a circuit wire 9 to the plug, the latter extending from a magneto spark coil or other source of electric distribution, commonly employed in connection with internal combustion engines of various kinds and classes.

The porcelain body includes a threaded collar l0, by means of which the core including the terminal 6 may be detachably mounted in connection with the body portion 11 of the plug. In the construction shown, the body portion 11 has a bore 12, in which the core 5 and terminal 6 is mounted. This bore is arranged eccentrically to the central axis of the body 11 so as to provide an enlarged portion 13 at body. The upper end of the body 1l has a hexagonal head 14, by means of which the plug may be attached and detached from the cylinder of an engine, the lower end of the body 11 being externally threaded as seen at 15 for mounting in the cylinder. Said end is provided with an enlarged bore 16, which is eccentric with respect to the bore 12 and in which is mounted our improved heatlng unit, plate or element, consisting of a bottom plate 17 secured to the lower end of the plug by spinning or otherwise turning over the lower edge of the plug as seen at 18, a conical portion 19 extending through an aperture formed in the plate 17 and riveted or spun over as seen at 20 to secure the cone 19 to the plate 17 and to provide an aperture 21 through which the lower end of the terminal 6 passes. The latter projects beyond the plate 17, as seen.

The conical portion 19 and plate 17 form within the enlarged bore 16, a chamber in which a heating coil 22 is arranged, the latter being coiled in conical form and arranged in a body of suitable insulating material 23. One end of the coil 22 is secured to the plate 17 as seen at 24, and the other end 25 extends through an aperture formed in the top flange of the conical Vportion 19 and through a bore 26 formed in the enlargement 13 of the plug body 11. The bore 26 extends upwardly and outwardly; and to insulate the wire 25 from the body l1, or the enlargement 13 thereof, two conical insulators 27 and 28 are disposed at each end of the bore 26 to maintain the wire centrally of the bore and out or" engagement with the wall of the body 11. At the free end of the wire 25 is a binding post 29 with which a circuit wire 30 controlling the heating coil 22 is adapted to be coupled, it being understood that the circuit of the coil 22 is a one-wire ground circuit, similar to that of the circuit of the plug, but is independent thereof and controlled by a suitable switch in the manner later described. The other terminal 31 of the spark plug is shown coupled with the lower end of the body 11 and arranged outwardly of the plate 17 and adjacent the lower end of the terminal, thus forming of the parts 6 and 31, the two points of the plug, or in other words, the sparking elements. It will be apparent that the terminal 31 may be attached to the plate 17, if desired, in that this plate is grounded with the body 11.

By providing the conical portion 19 in the heating unit, it will be seen that the interior of the plug may be readily cleaned by removing the core 5, the walls of t. e conical portion being substantially continuous with the walls of the bore 12 of the plug.

In the use of our -improved device, in the operation of initially stai ting an engine, the circuit to the coils 22 of the plugs in the several cylinders of the engine is eom'z-letcd through a suitable switch controlled by the operator, the circuit being closed a sufficient length of time to heat up the plate 17 as well as the conical portion 19, it being understood at his time, that this plate cannot be overheated by virtue of the fact that the heat will flow through the body portion of the plug and into the cylinder walls. After the plug has been heated, the engine will be started in the usual manner, and as the charge of fuel enters the cylinder, a portion of this charge surrounding the terminals or" the spark plug, such for example as represented by the dot and dash lines 32: become heated by the plate 17 to the el within this area. Thus, as the spark is completed between the points 6 and 3l of the spark plug, the vaporized fuel within the above ref to, will be ignited, causing the ignition of the remainder of the fuel charge in the cylinder, and thus effecting an instantaneous sta1 l, of the engine. When started, the circuit through the coil 22 is broken through. the manually controlled switch, as will be apparent.

By providing spark plugs made according to our invention in. internal combustion engines of Various kinds and cle eeially engines of motor vehicles, tr, tra-tors and the like, as well as the engines oi motor boats locomotives, these engines be quickly and easily started in the coldest l weather and regardless of the conditions of the no, assuming that a proper spark generated through the points of the spark plug, and that the ignition system is in proper working order. It must be corne in mind that the device is not intended to vaporize or preheat all of the fuel charged into the cylinder, but merely a sufficient amfrnt of this charge disposed adjacent .he spar elements to insure the firing of the vaporized fuel, and thus firing of the entire fuel charge in the respective cylinders of the engine,

It will also be understood that by virtue of the structure of our improved device, a preignition of the fuel charge will not be experienced as is the common experience of other` devices of this class employing exposed heating coils which would operate to instantaneously ignite the fuel charge into the engine, producing pre-combustion which is undesirable and apt to cause the explosion of the fuel stored in the carbureting device by virtue of the face that the intake valve of the engine is still open when. the pre-combustion takes place.

'Another feature of our improved spark plug` construction resides in the fact that the heating unit will operate to evaporate any moisture that may prevail at or around the sparking means or points of the plug and the adjacent walls of the plug and cylinder, as well to free, by virtue of the heat, any deposit of cil which may have collected thereon during the operation of the engine, thus insuring po. itive functioning of the plug through the vaporization of the fuel and maintaining the plug clean or free from moisture and oil deposits.

Qur improved device obviates the impracticability and inoperativeness of other devices of this class by virtue of the fact that the hot plate or element employed is capable of heating or vaporizing a relatively small portion of the fuel, and is not of sufficient heat to ignite or explode the initial fuel charge.

It will be understood that while we have shown a certain type of spark plug in the accompanying drawing, that our invention is not limited in this respect, nor are we limited to the specific structure of the heating element and its arrangement in connection with the plug as herein disclosed, and various other changes in and modifications of the structure herein set out may be made within the scope of the appended claims without departing from the spirit of our invention or sacriiicing its advantages.

Having fully described our invention, what we claim as new and desire to secure by Letters Patent, is:

1. A spark plug of the class described comprising a plug body, a bore arranged eccentrically of said body and extending therethrough, said bore being enlarged at the lower end of the body, the arrangement of the bore in said body forming an enlarged portion of the body at one side thereof, a plug core of insulating material detachably supported in connection with said body and extending into the bore thereof and including a terminal projecting through the lower end of the bore, another terminal at the lower end of the bore adjacent said first named terminal, and an electric heating element mounted in the enlargement of said bore and comprising a plate secured in the lower end of said bore and through which the f1rst named terminal passes, and a heating coil arranged in the enlargement of the bore inwardly of said plate, and means passed through the enlarged side portion of said body and insulated therefrom for placing said coil in circuit with one side of an electric circuit.

2. The combination with a spark plug including spark terminals at the inne end thereof, of a heating element comprising a plate secured within the lower end of the plug and having a central aperture through which one of the spark terminals passes, a conical. portion secured to the apertured portion of the plate and projecting into the plug to form said conical portion, an electric heating coil arranged in said chamber, one end of the coil being coupled with said plate and the other end thereof passing through the body of the plug and insulated therefrom, and means whereby a circuit in the lower end of the plug and having a central aperture through which one end of the spark terminals passes, a conical portion secured to the apertured portion of the plate and projecting into the plug to form an annular chamber around said conical portion, an electric heating coil arranged i in chamber, one end of the coil being coupled with said plate and the other end thereof passing through the body of the plug and insulated therefrom, means whereby a circuit wire may be cou- 4 pled therewith, and a body of insulating material l v` in s id chamber and around sail coil.

ALBERT GOODHEIM. WILLIAM R. MEYER.

an annular chamber around 

